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Preparation and primary evaluation of 66Ga-DTPA-chitosan in fibrosarcoma bearing mice
, Article Nukleonika ; Volume 56, Issue 1 , 2011 , Pages 41-47 ; 00295922 (ISSN) ; Pourjavadi, A ; Sharif University of Technology
Abstract
Chitosan was chemically modified by diethylenetetraaminepentaacetic acid (DTPA) in different degrees of modification (DM = 6.1, 10.3, 15.7 and 20.9%). DTPA-chitosans were radiolabeled with gallium-66 radionuclide. The effect of several factors on labeling yield such as degree of modification, acidity and concentration of DTPA-chitosan solution, contact time and radioactivity was investigated. Radiolabeled DTPA chitosans were intratumorally injected to fibrosarcoma bearing mice and the leakage of radioactivity from the injection site was evaluated. In comparison with chitosan, all DTPA chitosans showed better efficiency in preventing the leakage of radioactivity from tumor lesion and...
Stochastic modeling of degradation behavior of hydrogels
, Article Macromolecules ; Volume 51, Issue 11 , 2018 , Pages 3941-3952 ; 00249297 (ISSN) ; Abdekhodaie, M. J ; Chau, Y ; Sharif University of Technology
American Chemical Society
2018
Abstract
We describe here a theoretical framework to model the bulk degradation of hydrogels, which are prepared by chemical cross-linking of pendant functional groups on long polymer chains. The random order of the cleavage of degradable bonds was described by stochastic Monte Carlo simulation. The events of bond cleavage were related to the macroscopic changes of hydrogel by the Bray-Merrill equation. Next, the time for the gel to disintegrate was predicted by considering the relation between the recursive nature in breaking the cross-link nodes and gel-to-sol transition. To start the simulation, initial network properties including the number of active functional groups on the polymer chain and...